Monday, April 27, 2009

Interview with Christof Koch

GZ: How would you define the problem of consciousness?

CK: The problem is very difficult to define. We are conscious right now, when you ´re talking to me you are conscious, you can hear things, you can see things, you can remember things, that´ s what we mean by consciousness. It becomes very difficult to define it in more rigorous ways. There is an objective aspect, a feeling aspect, the feeling of being hungry, the feeling of seeing something, of seeing a bird, the feeling of remembering something, because of our conscious sensations. There are many things going in our body that don´ t involve consciousness. I can move my eyes, I can drive a car, I can climb, I can run, all those things bypass consciousness. Where’s the difference in between? To define it right now is not possible. However it is not necessary to define everything rigorously in order to advance. Historically, definitions only happen by hindsight. If you see the history of biology - genes for example - even today it’s not easy to define what’s a gene.

GZ: I see parallels between the difficulty of defining life and consciousness. Is there another parallel between the two that we should be aware of.CK: Depending on which philosophers you believe the problem of life was one of the big problems in early 20th century. People saw no way that chemistry and physics could allow the transmission of information from one generation to next. People said we know chemistry, we know physics, we know there’s no way that all the information that makes you up, your eye color, your height, can be just chemistry. What people didn’t realize was the ability of one dimensional change in macromolecules. They just didn’t know about this so they said well, we probably need new principles. So the lesson here is that we want to be cautious about what’s consciousness is. Many people say we need some fundamental new laws, but perhaps they are wrong, and consciousness can be explained when we discover the neural mechanism that evokes it.

GZ:Why is consciousness necessary for life?CK: It is very difficult to speculate its functions. I mean why do you have only two arms rather than four arms? You can suggest various reasons but it’s difficult to confirm. Human psychology seems to need consciousness. Say there is an earthquake or a fire, you know we have to do something we have never done before, we have to quickly get out, we have to leave the building etc. That’s an unplanned contingency, so that’s what I think we need consciousness for. However for most things that you typically do you do without consciousness.

GZ:You are studying vision. Why so? Why not the hearing system or some other body system?CK: It’s a tactical decision. I´ m a vision scientist, it’s my own personal interest. Also in vision we’ve learned to do things that are very difficult to do with any other body system, to manipulate the relationship between physical world and its subjective interpretation in a very precise way. We can use these techniques to manipulate the relationship between subjective person and physical stimulus, in order to track the footprints of consciousness in the brain.

GZ:The Holy Grail for neuroscientists is to identify the neural correlate of consciousness. What exactly is that?CK: It is the minimal set of neural mechanisms that are sufficient for consciousness in a person. Once we have the neural correlate of consciousness we can track what happens in diseases like schizophrenia and autism that intervene with consciousness, what happens in a newborn baby, how do we know that a newborn baby is conscious, or what happens in patients in a coma. Once we have the neural correlate we can begin to tackle these questions in a rigorous way.

GZ: Do you think that the so called “hard problem” will fade away?CK: Practically speaking, methologically speaking, conceptually speaking, intellectually speaking, it may turn out to be an easy problem. Because of the really difficult problem is that the brain is by far the most complex system in the known universe. We are missing many basic aspects. We don’t understand how very complicated networks of tens of thousands of millions neurons interact with each other. Once you understand this network, you say “oh that’s how it happened!”

GZ: Roger Penrose is suggesting what he calls “platonic realism” and says that consciousness is somehow a fundamental property of the universe and that through quantum effects it is being picked up from the brains and therefore we have qualia. What is your opinion?CK: Even if you assume quantum gravity to be relevant to the brain it doesn’t really make answer why quantum gravity should solve the hard problem. By involving yet another physical law, not just electromagnetism or chemistry, you introduce just another set of physical laws that do little to solve the mystery. Once you understand the brain as a classical device, then from the energies and the time scales involved, there’ s no evidence of any short of quantum superposition. I will stick with studying the brain as a classical rather than as a quantum system.

GZ:Why so many scientists are having a hard time accepting the fact that the brain can be explained?CK: It depends who you talk to. Biologists, physicists which are not much involved are generally skeptical, but not the neuroscientists that deal with the problem of consciousness. Anyway, I think there are many people on the planet who don’ t want to hear about this kind of research because they are afraid of the picture of humans that may emerge.

GZ: What is like working with Francis Crick?CK: I continue to work with him. It’s very intense. He’s 87 years old and he’s never seized to stop wondering, he’s never lost his curiosity and he is a person who, more than anybody else, questions every assumption, even his own assumptions.

GZ: You do rock climbing. How do you combine consciousness and rock climbing?

CK: Rock climbing is very intense and you have to focus when you do it. So it’s a bit like science, if you do it you are totally absorbed into it, because you cannot afford to do anything else.

GZ: Are you an optimist?CK: Of course I am an optimist.

GZ: You think is possible for science to enlighten people or is it a luxury only for an elite?CK: In the long term science is going to make people healthier, safer and happier, living longer lives, no question about that. This has been happening for the last 2.000 years and I see no reason why shouldn’t continue in the future.

GZ: So why most people read their horoscopes?CK: You got to ask them if they really believe in the horoscopes. Also many people believe in superstitions, but I don’t think that these things affect dramatically the way we generally think, which is, basically, rational.

(This is an edited transcript of an interview of Christof Koch, taken by George Zarkadakis on April 2004, in Tucson, AZ)